This invention relates to an inflatable escape slide for aircraft and more particularly to the connection between such an escape slide and the aircraft.
Inflatable escape slides are installed on virtually all passenger carrying aircraft to provide rapid evacuation of the passengers and crew during on-ground emergencies. Such escape slides generally include at least one inflatable member that is angularly deployed between the sill region of an elevated egress door and the surface of the ground or water. The upper surface of the inflatable member is configured to provide a sliding surface upon which the passengers and crew descend to the ground.
During normal aircraft operation, the deflated escape slide is generally packed in a compact package or container that is mounted either on the interior surface of the egress door or on the floor in front of the egress door. In most applications, the upper end of the escape slide includes a girt that encompasses a girt bar that is connected to brackets mounted on the floor inside the egress door. In the event of an on-ground emergency the door is opened and the escape slide is automatically or manually developed through the open doorway and inflated to form a slide between the door sill and the ground.
One of the problems encountered with inflatable aircraft escape slides is the lack of stabilization during deployment and use. Upsetting forces such as high winds may cause the escape slide to deploy improperly by twisting the slide into an unusable position or jamming the slide against the ground beneath the aircraft such that the passengers cannot descend safely. This problem has become decidedly more acute with the advent of large passenger aircraft, since these aircraft not only carry a larger number of passengers, but often include upper deck passenger areas that are located a substantial distance from the surface of the ground. Escape slides for deployment from the doorways of such an upper deck area are often 35 feet or more in length, and hence are more subject to upset during deployment and use.
One prior art attempt to stabilize an aircraft escape slide is disclosed in U.S. Pat. No. 3,669,217, issued to John M. Fisher. In this reference, the disclosed inflatable slide includes an inflatable positioning tube extending across the underside of the slide adjacent to the upper end thereof. During the deployment of the escape slide, the positioning tube is inflated and abuts the exterior surface of the aircraft fuselage prior to the full inflation of the slide. Effectively, the positioning tube forces the semi-inflated escape slide outward and upward from a vertical hanging position to counteract wind forces tending to blow the lower end of the slide underneath the aircraft fuselage.
Although the positioning tube disclosed by Fisher provides some degree of stabilization by resisting forces that could otherwise cause the slide to deploy improperly, the positioning tube would appear to provide minimal stabilization against forces that act to twist or rotate the slide around the axial centerline of the slide. Further, this prior art positioning tube does not seem to provide significant resistance to forces tending to laterally displace the lower end of the slide toward the nose or tail sections of the aircraft. Since external forces such as high wind gusts, obstacles on the ground or wave action in a situation where the aircraft executes an emergency landing in water, can exert forces on the slide during both deployment and use that tend to twist or laterally displace the lower end of the slide, the prior art positioning tube does not provide totally satisfactory performance. This is especially true with respect to the previously mentioned escape slides for use on large aircraft. For example, in an aircraft having both upper and lower passenger decks or compartments, the upper deck egress door may be located directly above, or nearly above, the lower deck egress door and the upper and lower deck escape slides designed to deploy in a side-by-side orientation. In such a configuration, lateral displacement of the upper deck escape slide can easily cause the upper deck slide to deploy directly over the lower deck slide to thereby render the lower deck slide unusable.
Accordingly, it is an object of this invention to provide support apparatus for an inflatable escape slide that stabilizes the inflatable escape slide against vertical, lateral and rotational forces during escape slide deployment and use.
It is a further object of this invention to provide support apparatus for use with an inflatable escape slide that is readily storable with the deflated escape slide during periods of nonuse and automatically deployable along with the inflatable slide during an emergency to form a stabilized escape slide for passenger evacuation.